Hardy Perennial Plants Growing Guide

The popularity of hardy perennial plants is due to many factors, not the least important being that they become permanent members of the garden and one can be reasonably sure of their annual appearance. They will certainly not flower so quickly from seed as will annual plants, but there is not the need to renew the plants each year. Few suffer from the effects of the most severe winter, and once established they will go on increasing in size year after year. The one drawback is that a few of the stronger growing plants may, after a few years, more than fill the space allotted to them, and they then need attention. Since, however, it is the younger outside portions of such plants as michaelmas daisies, Chrysanthemum maximum, solidago, phlox and the like which produce the finest blooms, the keen flower-grower will not find the task of dividing the roots at intervals irksome.

This is not the place to discuss in detail the difference in plants which are herbaceous perennials and those which are hardy perennials. Strictly speaking, an herbaceous perennial is a plant of which the top growth dies down in the autumn and reappears the following spring. Such a description might, of course, very well apply to many bulbous plants, but for our present purpose perennials are those plants which have fibrous roots. Even so, there are some truly herbaceous perennials, such as lupins and anchusas, which have thick, fleshy roots, as well as some fibrous ones. All of these may be increased vegetatively, when they will reproduce themselves with no variation.

Our concern, however, is to deal with cut-flower subjects. It is possible to raise many perennial plants from seed, the quickest way to obtain a good supply of flowers from hardy perennials is to secure plants. There is a tremendously wide range available. A selection is therefore given with no pretence of its being a complete list. There are many plants which are rarely, if ever, available in the florists’ shops, although it is noticeable that the range today is much greater than it was before the last war.

In listing perennials suitable for cutting one is almost certain to leave out some which others have found very useful, while only certain

species and varieties of any particular genus may be of use as cut flowers.

Any special soil requirements, or possible pests and diseases, will be mentioned as each plant is dealt with. I sincerely believe, however, that it is unnecessary for a good gardener to be greatly troubled with diseases. Many of the quite common ailments are bound up with wrong soil conditions, often brought about by lack of humus or organic matter, coupled with the continuous applications of artificial fertilisers.

There is no doubt that a good border or bed of perennial plants can be a real asset to any garden, whatever its size. It is true that we cannot have all the plants in flower all the time, but we can, with care, select plants so that there is colour almost, if not all, the year round.

We may plan such borders, and arrange our planting accordingly, in one of two designs or patterns. The first is the informal design, wherein the whole composition and subsequent results depend on the plants themselves. The second is the formal pattern, which may be the result of the actual placing of the plants, but is more likely to be a design of some kind already in existence. In the latter case it may be that quite big patches of earth will be seen, whereas with the informal grouping of an herbaceous border the whole effect may be spoiled by leaving spaces. This does not mean, of course, that plants which die down in the winter are unsuitable.

There is also another important angle to consider, and that is the association of one class of plant with another. It is not easy to suggest any rules which may or should govern the compatibility of plants, for it does not depend on botanical relationship or the need of certain plants for similar culture. In the end it comes back to the actual character of the plants themselves, although again this is hard to put into words.

Therefore, the makers of good herbaceous borders need, and often have, qualities not always credited to them, even when they have made a successful job of designing and planting a completely satisfactory plant border, capable of yielding cut flowers over a period of many months.

While a border of graduating heights may have its advantages, it looks formal. My own preference is for the arranging of plants with differing habits of growth, side by side. This means that we shall not have all the plants with more or less upright foliage, such as irises and kniphofia, growing together, but other subjects with a different manner of growth will be used as near companions. There is also the need for plants with low-growing, widish leaves to provide a kind of steadying base to the tall, spiral flower-stems of many subjects used in the border.

There should be contrasts and harmonies in the colouring of the foliage, and with a little forethought it is possible to use plants not only having foliage with coloured tones but in very many shades of green. Very often these are ideal for arranging with cut flowers. Some big-leaved plants, such as gunnera, rheum and rodgersia, which may be used in a very large border, would be quite out of place in the average garden.

Although not favoured by all garden-lovers, I see no objection to including a few well-chosen shrubs in the herbaceous border; as a background I consider they are often ideal. In the early summer, shrubs such as philadelphus, lilac and weigela seen behind delphiniums and lupins look very attractive. One or two of the smaller-growing berberises with their coloured foliage, as well as their flowers and sometimes berries, also give a good impression as do a plant or two of lavender and rosemary.

Sufficient has been said to indicate that the herbaceous border need not be what it is so often—just a place where perennial plants are put!